Printed-wiring boards to be used for electronic equipments such as computers are those prepared by forming a determined pattern of wiring of copper or the like on one or both sides of an insulating substrate.
Printed-wiring boards of this kind may be prepared by the following manufacturing steps.
First, a laminate consisting of a photosensitive resin (photoresist) layer and a translucent resin film (protective layer) protecting the photosensitive resin layer is laminated by thermocompression bonding on a conductive layer mounted on an insulating substrate. The lamination by thermocompression bonding may be conducted on a large scale using a film laminating apparatus or a so-called laminator. Thereafter, a wiring pattern film is placed on the laminate, and the photosensitive resin layer is exposed for a determined period of time through the wiring pattern film and the translucent resin film. After the translucent resin film is peeled off using a peeling device, the exposed photosensitive resin layer is developed to form an etching mask pattern. Thereafter, unnecessary portions of the conductive layer are removed by means of etching and further the remaining photosensitive resin layer is removed, thereby leading to a printed-wiring board with a predetermined wiring pattern.
In the manufacturing steps of the printed-wiring boards as described above, it is necessary to use the step of exposing the photosensitive resin layer by superposing the wiring pattern film on the laminate laminated on the substrate by thermocompression bonding. This superposition is carried out by fitting a positioning pin in a guide hole (positioning hole) formed at a corner or end portion of the substrate and a guide hole (positioning hole) formed on the wiring pattern film so as to correspond to the above guide hole. Since the laminate is laminated on the substrate, a hole for fitting the positioning pin is formed on the laminate at the position corresponding to the guide hole on the substrate prior to the fitting of the positioning pin. The punching on the laminate may be conducted manually using a drill or a punch or mechanically using a punching device for exclusive use after the laminate has been laminated on the substrate by thermocompression bonding. However, manual or mechanical punching of the laminate causes problems, resulting in extremely poor work efficiency.
In forming a hole on the laminate, chips of the laminate are scatter on the laminate on which a wiring pattern is formed and it is extremely hard to clear such chips. This prevents the wiring pattern from being drawn accurately on the photosensitive resin layer, resulting in a decrease in a yield in the manufacture of printed-wiring boards.